Improvement in potato-diggers



2 Sheets-Sheet 1. A. J. ROBERTSON. V

POTATO-DIGGER. Na. 192,013. Patented-June 12,1877.

UNITED STATES- ?ATENT OFFICE.

ALBERT l-ROBERTSON, OF MONROE, MAINE.

IMPROVEMENT IN POTATO-DIGGERS.

Specification forming part of Letters Patent No. 192,0i3. dated June 12, 1877 5 application filed April 14. 1877.

To all whom it may concern Be it known that I, ALBERT J. ROBERT- SON, of Monroe, in the county of Waldo and State of Maine, have invented certain new and useful Improvements in Potato-Diggers; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to which is appertains to make and use the same, referencebeing had to the accompanying drawings, and to the letters of reference marked. thereon, which form a part of this specification.

Figure 1 is a top plan view. Fig. 2 is a side view, the wheel being removed; and Fig. 3 is a longitudinal vertical section.

Similar letters of reference indicate correing solid wheels E E, which maybe of any suitable construction. To the'axle B is keyed a gear-wheel, 0. 0 is a shaft, having its bearings in side pieces a a. behind axle B, having on its square end, which projects beyond frame-piece a, a sliding pinion, d, operated by a lever, D, by which it may, at any time, be thrown into gear with the wheel 0 on axle B.- G is a shaft, having its bearings in side pieces a a at the front end of frame A. F is the elevator. This consists of belts or, chains f f, running upon disks or wheels 9 h keyed upon shafts G G, and united by cross-pieces e 6, having fingers t i.

H is a scoop attached to the front end of frame A. To the rear under side of this scoop are secured, by set-screws, or in any other suitable manner, long metal rods or bars 1c 7a, the ends of which (which should reach beyond shaft 0 in the rear part of the frame) are curved in adownward direction, as shown at k. i The bars 70 70 form a perfect sieve or screen, through which the dirt is sifted out as the potatoes are being carried by the elevator F to the box K, the sides and end of which are formed by the side pieces a a and end piece a of frame A. g

The bottom of the box K is pivoted between the end piece a. and a cross-brace, t", and is operated by a suitably-arranged lever, L, by which it may be tipped to either side, so as to deposit its contents on either side of the machine.

M is the tongue. This is hinged atm to the rear cross-brace b of frame A, and it has a bent lever, N, connected to a bail, 0, the ends of which are pivoted in the sides of scoop H. By operating lever N the front end of the machine, with the scoop, may be raised or lowered, and the depth at which the scoop is to dig is in this manner gaged.

The disks g 9 upon shaft 0 are connected by metal rods 9 g, thus forming a perfect cylindrical screen, which, as the potatoes are being carried by the elevator off the bars 70 and into the box, prevents them from dropping on the ground.

The operation of my improvedpotato-digger is as follows:

The scoop H being set or gaged by the lever N, the machine is dragged over the field, one of the wheels E running on each side of therow. The potatoes,dirt,&c.,slide up upon the scoop until caught by the fingers t of the elevator-bars e, (the elevator being operated by the pinion d upon shaft 0, gearing with the cog-wheel 0 upon axle B.) The fingers t slide between the bars It of the screen, thus carrying the potatoes up, while the dirt and sand escape between bars 70. Each time one of the cross-bars 0 passes under the curved ends of bars h it raises these, which, when In a potato-digger, the combination of the In testimony that I claim the foregoing as screen-bars k k, attached to the rear end of the my own I have hereto affixed my signature in scoop H, and having down'wardly-cnrved free presence off'two Witnesses. rear ends, in combination with the elevator F arranged underneath, and having cross-bars ALBERT J. ROBERTSON. e e, which, by striking against the rear ends of the screen-bars k k, impart to these a tr em- Witnesses bling or vibratinginotibn, substantially a's'de- *J."H. ROBERTSON,

scribed, for the purpose shown and specified. E. W. Dow. 

